Softwr

Documentation · head to head

Grammarly vs Vellum

Grammarly logo

Grammarly

Documentation

Great writing, simplified

From
Free
Rated
-
Full reviewWebsite
Vellum logo

Vellum

AI

Personalized AI assistant with persistent memory and autonomous action-taking

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Grammarly occasional false positives and grammatically incorrect suggestions that can introduce errors; Vellum pricing varies significantly by computational tier, making budget planning difficult
  • They diverge on capability: Grammarly covers Grammar checking, Vellum covers Persistent AI identity.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Grammarly and Vellum actually diverge.

Attributes where Grammarly and Vellum differ
AttributeGrammarlyVellum
Pricing modelUnknownFreemium with paid plans and pay-as-you-go credits
PlatformsWeb, macOS, Windows, iOS, AndroidWeb, macOS, iOS, Slack, Telegram, Terminal
CategoryDocumentationAI
Founded2009Unknown

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Grammarly

  • Grammar checking
  • Spelling correction
  • Punctuation
  • Clarity suggestions
  • Engagement feedback
  • Delivery insights
  • Plagiarism checker
  • Citation generator

Only in Vellum

  • Persistent AI identity
  • Long-term memory
  • Email automation
  • Calendar management
  • Autonomous task execution
  • Multi-device synchronization
  • Custom plugins
  • Open-source deployment

What people use each for

The jobs each tool is most often brought in to do.

Grammarly

  • Email writingnot Vellum
  • Document editingnot Vellum
  • Academic writingnot Vellum
  • Business communicationnot Vellum
  • Content creationnot Vellum

Vellum

  • Personal productivity automation across email and calendarnot Grammarly
  • CRM updates and pipeline managementnot Grammarly
  • Expense report generation and managementnot Grammarly
  • Document drafting and content creationnot Grammarly
  • Meeting scheduling and calendar coordinationnot Grammarly

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Grammarly

  • Occasional false positives and grammatically incorrect suggestions that can introduce errors
  • Privacy concerns about sending text to Grammarly's servers for analysis
  • AI capabilities sometimes produce hallucinations and fabricated citations that appear grammatically correct

Vellum

  • Pricing varies significantly by computational tier, making budget planning difficult
  • Requires explicit permission for sensitive actions, limiting autonomy
  • Self-hosting option may intimidate non-technical users
  • Learning curve to develop customizations with plugins

Pricing, plan by plan

Grammarly

Free
  • FreeFree
    • Basic grammar and spelling checks
    • Tone visibility
    • 100 AI prompts per month
  • Pro$12/month
    • Sentence rewrites
    • Tone adjustment
    • Plagiarism and AI detection

Vellum

Free
  • FreeFree
    • Starter credits included
    • Basic features
  • Mighty$30/month
    • 1 vCPU, 2 GiB RAM
    • 10 GB storage
    • Included usage allowance
  • Super$100/month
    • 2.5 vCPU, 5 GiB RAM
    • 30 GB storage
    • Assistant email and subdomain
  • Ultra$200/month
    • 4 vCPU, 8 GiB RAM
    • 60 GB storage
    • Assistant email and subdomain

Which should you pick?

Choose Grammarly if

  • You need grammar checking.
  • You want to start without paying.
  • You work on Web, macOS, Windows, iOS, Android.
  • You also want spelling correction.
Grammarly review

Choose Vellum if

  • You need persistent ai identity.
  • You want to start without paying.
  • You work on Web, macOS, iOS, Slack, Telegram, Terminal.
  • You also want long-term memory.
Vellum review

Questions people ask

Is Grammarly or Vellum better?
Neither clearly leads. Grammarly starts at Free and Vellum at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Grammarly or Vellum?
Grammarly starts at Free and Vellum at Free.
Does Grammarly or Vellum run on more platforms?
Grammarly runs on Web, macOS, Windows, iOS, Android. Vellum runs on Web, macOS, iOS, Slack, Telegram, Terminal.
Can I use Grammarly for free?
Both have a free tier, so you can try either at no cost before committing.
What is Grammarly best used for?
Grammarly is most often used for email writing, document editing, academic writing, business communication. Of those, email writing and document editing are not what Vellum is typically brought in for.
What can Grammarly do that Vellum cannot?
Grammarly covers Grammar checking, Spelling correction, Punctuation, Clarity suggestions. Vellum covers Persistent AI identity, Long-term memory, Email automation, Calendar management.

Answered from the vendors’ own pages

Grammarly: Does Grammarly have a free version?

Yes, Grammarly offers a free tier with basic spelling, grammar, and punctuation checks, tone visibility, and 100 AI prompts per month. The Pro plan ($12/month annual) adds sentence rewriting, plagiarism detection, and 2,000 AI prompts.

Source
Vellum: How does Vellum protect my data privacy?

Vellum uses permission-based controls requiring explicit approval for sensitive actions. Data is encrypted and the option for self-hosting provides complete data control. Open-source deployment option allows hosting on your own infrastructure.

Source
Grammarly: What platforms does Grammarly work with?

Grammarly works across 1 million+ apps including Google Docs, Microsoft Word, Outlook, Slack, Gmail, and web browsers. It also integrates with productivity tools like Asana, Jira, Monday.com, Confluence, and HubSpot.

Source
Vellum: Can I use Vellum for business team collaboration?

Vellum is primarily designed as a personal assistant with persistent identity. For team collaboration, platforms like Lindy offer better multi-user features with shared credit pools and Slack workspace integration.

Source
Grammarly: Can I use Grammarly offline?

Grammarly requires an internet connection to function, though the browser extension works with some offline text areas. For offline use, the desktop app and browser extensions sync when reconnected.

Source
Vellum: What does the free tier include?

Vellum offers free starter credits to begin using the platform. Beyond that, it operates on a pay-as-you-go credit model with paid tiers starting at $30/month for increased computational resources and bundled credits.

Source
Grammarly: What is included in the Enterprise plan?

The Enterprise plan includes unlimited team members, dedicated support, custom roles and permissions, data loss prevention, bring-your-own-key encryption, and unlimited AI prompts. Pricing is custom and available by contacting sales.

Source
Share

Related pages

More on Grammarly

More on Vellum

Keep looking

Other head to heads